The present research is aimed at better understanding the "conversation" between "affective" and "cognitive" processes that initiates in adolescence. Described below are a series of longitudinal studies that will examine the structure and function of a specific neural system in the developing brain. Structural and functional MR, as well as behavioral measures will be applied to this issue. It is the goal of this work to bring convergent imaging technologies to bear on the relation of brain and mind in the developing adolescent. The current project is directed at understanding the development of the functional connectivity between medial temporal lobe structures, and frontal cortex. It is hypothesized that maturation of these reciprocal projections may be associated with increased cognitive ability, as well as significant improvements in affective competencies and emotional regulation. The maturation of these circuits is believed to be essential for the behavioral milestones required for a successful transition from childhood to adulthood. It is additionally hypothesized that specific types of psychopathology may be associated with perturbation of this developmental sequence. There are three phases to the proposed project that serve to mutually inform one another. Structural MR imagining (both high resolution structural imaging and diffusion tensor imaging), functional neuroimaging, and behavioral measures will be collected from a group of adolescent subjects longitudinally during their adolescence. The investigator will examine the relationships among functional anatomy, morphology, and behavioral performance on cognitive and affective challenge paradigms. Through the acquisition of longitudinal data the investigator hopes to establish correlates which typify neurobiological changes associated with this period of development.